Assessment on the Utilization of Surface Water Resources in the Mainstream Watershed of the Tarim River since Recent 5 Decades

There is no the runoff formation in the mainstream watershed of the Tarim River. The mainstream of the Tarim River was converged by 9 main stream systems, it, however, is currently converged by 3 main stream systems only, i.e., the Aksu River, Hotan River and Kaidu River-Kongque River, and its ecosystems are maintained by these three stream systems. Since recent 5 decades, the stream flow of the mainstream of Tarim River has been obviously reduced due to the extensive human activities dominated by the exploitation and utilization of water resources in the source stream areas although the stream flow out of the debouchures is not reduced and even increased since the 1990's. Moreover, the water consumption is continuously increased, the average annual water consumption is 1.689×109 m3 in the upper reaches of the mainstream of Tarim River and 2.296×109 m3 in the middle reaches, the water consumption in the upper and middle reaches occupies 86.3% of the average annual runoff volume (4.618×109 m3) at Aral Hydrological Station, and only an average annual runoff volume of 6.33×109 m3, occupying 13.7% of the average annual runoff volume, can flow to the lower reaches. The Daxihaizi Reservoir located in the lower reaches was built in 1970, and then there was no stream flow flowing downstream from the reservoir in 20 years among the 30 years from 1970 to 1999. Thus, a river channel section of 320 km in length and the Taitema Lake in the lower reaches were dried up, the area of the desert was enlarged, the desertification became more serious, and the ecology was degenerated in the lower reaches of mainstream of Tarim River.Five times of the urgent stream water transfusion from the Bosten Lake to the mainstream of Tarim River were implemented during the period from May 14, 2000 to November 3, 2003, the total discharged stream water volume downstream from the Daxihaizi Reservoir was 1.66×109 m3. Thus, the water area of the Taitema Lake dried up for 28 years was larger than 10 km2 on November 16, 2001, and the ecology and environment along the river channel in the lower reaches of the Tarim River are currently improved.